Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 211
Filtrar
2.
Org Lett ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33078953

RESUMO

A diastereodivergent synthesis of α-chiral tertiary azides through catalytic enantioselective Michael addition of α-azido indanones to ß,γ-unsaturated α-ketoesters is described. The merger of a newly designed bifunctional phosphoramide C4b and hexafluoroisopropanol (HFIP) affords syn-adducts, whereas the use of thiourea C6a provides anti-adducts without the aid of HFIP. Notably, additive HFIP proves to be the key control element to achieve diastereoselectivity reversal in the former case. The products are readily converted to enantioenriched spiro N-heterocycles.

4.
J Int Med Res ; 48(6): 300060520925948, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32600079

RESUMO

OBJECTIVE: This study investigated the frequency of T-helper (Th)17 lymphocytes and production of cytokine interleukin (IL)-17 in peripheral blood of patients with non-small-cell lung cancer (NSCLC) and their use as a marker of clinical value. METHODS: Sixty patients with NSCLC and 60 healthy volunteers were enrolled in the study. Flow cytometry was used to detect the frequency of Th17 lymphocytes in peripheral blood, and enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of IL-17. We analyzed the association of Th17 lymphocytes and IL-17 levels in the peripheral blood of patients with their clinicopathological features. RESULTS: Frequency of Th17 lymphocytes and production of IL-17 were significantly higher in the NSCLC group than in the control group and were higher in patients with a smoking history compared with non-smokers. Moreover, Th17 lymphocyte and IL-17 expression levels were higher in patients with squamous cell carcinoma than in patients with adenocarcinoma, and significantly higher in patients with stage III and IV cancers than in patients at stage I or II. CONCLUSION: Th17 lymphocytes and IL-17 play an important role in the development of NSCLC in patients and may have clinical value as markers for treatment of NSCLC.

5.
Virol Sin ; 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32720213

RESUMO

Tyro3, Axl, and Mertk (TAM) receptors play multiple roles in a myriad of physiological and pathological processes, varying from promoting the phagocytic clearance of apoptotic cells, sustaining the immune and inflammatory homeostasis, maintaining the blood-brain barrier (BBB) integrity and central nervous system (CNS) homeostasis, to mediating cancer malignancy and chemoresistance. Growth arrest-specific protein 6 (Gas6) and protein S (Pros1) are the two ligands that activate TAM receptors. Recently, TAM receptors have been reported to mediate cell entry and infection of multitudinous enveloped viruses in a manner called apoptotic mimicry. Moreover, TAM receptors are revitalized during viral entry and infection, which sequesters innate immune and inflammatory responses, facilitating viral replication and immune evasion. However, accumulating evidence have now proposed that TAM receptors are not required for the infection of these viruses in vivo. In addition, TAM receptors protect mice against the CNS infection of neuroinvasive viruses and relieve the brain lesions during encephalitis. These protective effects are achieved through maintaining BBB integrity, attenuating proinflammatory cytokine production, and promoting neural cell survival. TAM receptors also regulate the programmed cell death modes of virus-infected cells, which have profound impacts on the pathogenesis and outcome of infection. Here, we systematically review the functionalities and underlying mechanisms of TAM receptors and propose the potential application of TAM agonists to prevent severe viral encephalitis.

7.
J Virol ; 94(17)2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32611752

RESUMO

Japanese encephalitis virus (JEV) is a flavivirus that causes Japanese encephalitis (JE), which has an unclear pathogenesis. Despite vaccination, thousands of deaths attributed to JE are reported annually. In this study, we report that mice deficient for Axl, a receptor tyrosine kinase that plays multiple roles in flaviviral infection, displayed greater mortality upon JEV infection. The effect of Axl deficiency on JEV infection was mediated by markedly elevated serum interleukin-1α (IL-1α) levels, which devastated the blood-brain-barrier and promoted viral neuroinvasion within 24 h postinfection. Using an in situ infection model, we showed that dead macrophages were the primary source of observed increased serum IL-1α levels. Axl deficiency enhanced cell death and caused pyroptosis in 80% of JEV-infected macrophages by disrupting phosphatidylinositol 3-kinase (PI3K)-Akt signaling. Intriguingly, the primary effector released by pyroptotic macrophages in our model was IL-1α rather than IL-1ß. Finally, we assessed the effect of an IL-1α antagonist and demonstrated that it effectively prevented the incidence of JE. Our results indicate that Axl plays a protective role in JEV infection, identify IL-1α released by pyroptotic macrophages as a crucial factor promoting JEV neuroinvasion, and suggest that an IL-1α antagonist may be a candidate for JE therapy.IMPORTANCE Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes Japanese encephalitis (JE), the most commonly diagnosed viral encephalitis worldwide. The fatality rate of JE is 20%, and nearly half of the surviving patients develop neuropsychiatric sequelae. Axl is a receptor tyrosine kinase that plays multiple roles in flaviviral infections. Currently, the involvement of Axl in JEV infection remains enigmatic. In this study, we demonstrate that Axl impedes the pathogenesis of severe JE in mice by maintaining blood-brain-barrier (BBB) integrity and restricting viral neuroinvasion. Furthermore, serum IL-1α is a key mediator of this process and is primarily released by JEV-infected pyroptotic macrophages to elicit BBB breakdown, while an IL-1α antagonist can effectively reduce the incidence of severe JE. Our work uncovers the protective role of Axl in antagonizing severe JE and shows that the use of an IL-1α antagonist may be a promising tactic to prevent severe JE.

8.
Sci Rep ; 10(1): 12731, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32728176

RESUMO

Dengue fever is a mosquito-borne disease caused by the dengue virus. Aedes aegypti (Ae. Aegypti) is considered the primary vector of Dengue virus transmission in Yunnan Province, China. With increased urbanization, Ae. aegypti populations have significantly increased over the last 20 years. Despite all the efforts that were made for controlling the virus transmission, especially on border areas between Yunnan and Laos, Vietnam, and Myanmar (dengue-endemic areas), the epidemic has not yet been eradicated. Thus, further understanding of the genetic diversity, population structure, and invasive strategies of Ae. aegypti populations in the border areas was vital to uncover the vector invasion and distribution dynamic, and essential for controlling the infection. In this study, we analyzed genetic diversity and population structure of eight adult Ae. Aegypti populations collected along the border areas of Yunnan Province in 2017 and 2018. Nine nuclear microsatellite loci and mitochondrial DNA (mtDNA) sequences were used to achieve a better understanding of the genetic diversity and population structure. One hundred and fourteen alleles were found in total. The polymorphic information content value, together with the expected heterozygosity (He) and observed heterozygosity (Ho) values showed high genetic diversity in all mosquito populations. The clustering analysis based on Bayesian algorithm, the UPGMA and DAPC analysis revealed that all the eight Ae. aegypti populations can be divided into three genetic groups. Based on the mtDNA results, all Ae. aegypti individuals were divided into 11 haplotypes. The Ae. aegypti populations in the border areas of Yunnan Province presented with high genetic diversity, which might be ascribed to the continuous incursion of Ae. aegypti.

11.
Artigo em Inglês | MEDLINE | ID: mdl-32417717

RESUMO

The aim of this study was to investigate the differences in volatile organic compounds (VOCs) obtained from the feces of a Baihe Jizihuang Tang (BHT)-treated rat depression model. Rats were subjected to chronic unpredictable mild stress (CUMS), and the differences in VOCs were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), NIST software, principal component analysis, and orthogonal partial least squares discriminant analysis. Eleven biomarkers were identified on the basis of VOC migration time, and their relative peak intensities were analyzed. A metabonomic model was established using multivariate statistical analysis. The study demonstrated the metabonomics of CUMS rats and the intervention effect of BHT and also highlighted the potential therapeutic effects of the traditional Chinese medicine (TCM) Jingfang for the clinical treatment of complex diseases, which was in line with the holistic and systemic approaches of TCM. This study augments the use of metabonomics based on HS-GC-IMS in research studies. Using this method, there is no need to pre-process samples by extraction or derivatization, and the VOC component of the sample can be detected directly and rapidly. In conclusion, this study establishes a simple, convenient, and fast technique, which can help identify clinical biomarkers for rapid medical diagnosis.

12.
J Pharmacol Sci ; 143(3): 165-175, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32387002

RESUMO

yeyachun and danshen exist as Chinese patent medicine, Xuemai Tong, and are clearly effective at alleviating liver fibrosis (LF). Previous studies have indicated that triterpenoids from yeyachun (EFT), and phenolic acids from danshen (SMP) are effective in the treatment of LF. The regulation of intestinal flora is an effective method for treating LF. The aim of this study was to investigate the effect of a mixture of EFT and SMP on carbon tetrachloride (CCl4) induced LF. Our results showed the mixture significantly decreased liver damage and fibrosis index, and maintained liver tissue composition, compared to the model group. Moreover, the imbalance of symptoms of intestinal flora was improved. The mixture also caused changes to metabolites of gut flora. Furthermore, the expression of CD68 in liver tissues from the treated groups was significantly decreased when compared to the model group. However, no significant difference was observed from microstructure of gut tissues and LPS concentrations in the serum between mixture treated mice and model mice. This study suggests that the mixture of EFT and SMP had a significant effect on CCl4 induced LF, and the mechanism of this action, at least in part, involved the regulation of intestinal flora and their metabolites.


Assuntos
Tetracloreto de Carbono/efeitos adversos , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Microbioma Gastrointestinal/efeitos dos fármacos , Hidroxibenzoatos/farmacologia , Hidroxibenzoatos/uso terapêutico , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/microbiologia , Fitoterapia , Salvia miltiorrhiza/química , Triterpenos/farmacologia , Triterpenos/uso terapêutico , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/isolamento & purificação , Fígado/metabolismo , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Masculino , Camundongos Endogâmicos ICR , Triterpenos/isolamento & purificação
13.
Am J Respir Crit Care Med ; 202(5): 730-744, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32421376

RESUMO

Rationale: Platelets are generated in the capillaries of the lung, control hemostasis, and display immunological functions. Tuberculosis primarily affects the lung, and patients show platelet changes and hemoptysis. A role of platelets in immunopathology of pulmonary tuberculosis requires careful assessment.Objectives: To identify the dynamics and interaction partners of platelets in the respiratory tissue and establish their impact on the outcome of pulmonary tuberculosis.Methods: Investigations were primarily performed in murine models of primary progressive pulmonary tuberculosis, by analysis of mouse strains with variable susceptibility to Mycobacterium tuberculosis infection using platelet depletion and delivery of antiplatelet drugs.Measurements and Main Results: Platelets were present at the site of infection and formed aggregates with different myeloid subsets during experimental tuberculosis. Such aggregates were also detected in patients with tuberculosis. Platelets were detrimental during the early phase of infection, and this effect was uncoupled from their canonical activation. Platelets left lung cell dynamics and patterns of antimycobacterial T-cell responses unchanged but hampered antimicrobial defense by restricting production of reactive oxygen species in lung-residing myeloid cells.Conclusions: Platelets are detrimental in primary progressive pulmonary tuberculosis, orchestrate lung immunity by modulating innate immune responsiveness, and may be amenable to new interventions for this deadly disease.

15.
Front Immunol ; 11: 162, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32174909

RESUMO

Neuroinflammation induced by overactivated glia cells is believed to be a major hallmark of Alzheimer's disease (AD) and a hopeful target against AD. A rhamnoside PL201 was previously reported to promote neurogenesis and ameliorate AD, and in this study, we revealed that PL201 also significantly reduced accumulation of the activated microglia and proinflammatory cytokines in APP/PS1 mice. In vitro, PL201 consistently suppressed the microglia induction of proinflammatory cytokines after stimulation with lipopolysaccharides and Aß42. Further mechanistic studies demonstrated that PL201 considerably enhanced the expression level and the nuclear translocation of Nrf2, a key regulator of neuroinflammation. Moreover, PL201 effectively stimulated Nrf2 signaling cascade, including upregulation of HO-1 and downregulation of NF-κB pathway. Thus, our findings indicated the anti-neuroinflammatory effect by PL201 in vivo and suggested that PL201 or the like, with multiple functions such as neurogenesis, mitochondria maintenance, and anti-neuroinflammation, could be a promising candidate in AD treatment.

16.
Viruses ; 12(3)2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32213866

RESUMO

The Japanese encephalitis virus (JEV) is a Culex mosquito-borne flavivirus and is the pathogenic agent of Japanese encephalitis, which is the most important type of viral encephalitis in the world. Macrophages are a type of pivotal innate immunocyte that serve as sentinels and respond quickly to pathogen invasions. However, some viruses like JEV can hijack macrophages as a refuge for viral replication and immune escape. Despite their crucial involvement in early JEV infection, the transcriptomic landscapes of JEV-infected macrophages are void. Here, by using an in situ JEV infection model, we investigate the transcriptomic alteration of JEV-infected peritoneal macrophages. We found that, upon JEV infection, the macrophages underwent M1 polarization and showed the drastic activation of innate immune and inflammatory pathways. Interestingly, almost all the programmed cell death (PCD) pathways were activated, especially the apoptosis, pyroptosis, and necroptosis pathways, which were verified by the immunofluorescent staining of specific markers. Further transcriptomic analysis and TUNEL staining revealed that JEV infection caused apparent DNA damage. The transcriptomic analysis also revealed that JEV infection promoted ROS and RNS generation and caused oxidative stress, which activated multiple cell death pathways. Our work uncovers the pivotal pathogenic roles of oxidative stress and multiple PCD pathways in JEV infection, providing a novel perspective on JEV-host interactions.

17.
Oxid Med Cell Longev ; 2020: 7698560, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32104538

RESUMO

Oxidative stress-induced mitochondrial dysfunction and cell senescence are considered critical contributors to Alzheimer's disease (AD), and oxidant/antioxidant imbalance has been a therapeutic target in AD. SIRT3 is a mitochondrial protein regulating metabolic enzyme activity by deacetylation and its downregulation is associated with AD pathology. In the present study, we showed that a newly synthesized rhamnoside derivative PL171 inhibited the generation of reactive oxidant species (ROS) induced by amyloid-ß 42 oligomers (Aß 42O), major AD pathological proteins. Moreover, the reduction of mitochondrial membrane potential (MMP) and the impairment of mitochondrial oxygen consumption triggered by Aß 42O were also prevented by PL171. Further experiments demonstrated that PL171 reduced the acetylation of mitochondrial proteins, and particularly the acetylation of manganese superoxide dismutase (MnSOD) and oligomycin-sensitivity-conferring protein (OSCP), two mitochondrial SIRT3 substrates, was suppressed by PL171. Mechanism studies revealed that PL171 upregulated SIRT3 and its upstream peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) under basal and Aß 42O-treated conditions. The inhibition of SIRT3 activity could eliminate the protective effects of PL171. Further, long-term treatment with Aß 42O increased the number of senescent neuronal cell, which was also alleviated by PL171 in a SIRT3-dependent manner. Taken together, our results indicated that PL171 rescued Aß 42O-induced oxidative stress, mitochondrial dysfunction, and cell senescence via upregulating SIRT3 and might be a potential drug candidate against AD.

18.
Sci Rep ; 10(1): 2971, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32060367

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

19.
Stem Cells ; 38(5): 653-665, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32052915

RESUMO

The intricate balance of neural stem cell (NSC) amplification and neurogenesis is central to nervous system development. Dopamine D1 receptor (DRD1) is a typical G protein-coupled receptor (GPCR) mainly expressed in neurogenic area, with high constitutive activity. The receptor appears in the embryonic period before the formation of mature synaptic contacts, which indicates that dopamine receptor and its constitutive activity play crucial roles in the embryonic brain development. Here, we found that DRD1 was enriched in human NSCs. Inhibition of the receptor activity by its inverse agonists promoted human NSCs proliferation and impeded its differentiation. These results were also mimicked by genetic knockdown of DRD1, which also blocked the effects of inverse agonists, suggesting a receptor-dependent manner. More interestingly, knock-in A229T mutant with reduced DRD1 constitutive activity by CRISPR-Cas9 genome editing technology resulted into increased endogenous human NSCs proliferation. These results were well reproduced in human cerebral organoids, and inhibition of the DRD1 constitutive activity by its inverse agonists induced the expansion and folding of human cerebral organoids. The anatomic analysis uncovered that decreasing the constitutive activity of DRD1 by its inverse agonists promoted the NSCs proliferation and maintenance that led to hindered cortical neurogenesis. Further mechanistic studies revealed that the PKC-CBP pathway was involved in the regulation by DRD1. Thus, our findings indicate that the constitutive activity of DRD1 and possibly other GPCRs plays an important role in the development of human nervous system.

20.
Int J Behav Med ; 27(4): 400-405, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32096097

RESUMO

BACKGROUND: Adverse childhood experiences (ACEs) have been linked to long-term health outcomes, while the impact of such experience has not been investigated among Zambian youth. This study examined the associations of ACEs with individual and clusters of health risk behavior among college students in Zambia. METHOD: A total of 624 college students participated in this cross-sectional study. A self-administered questionnaire was used to collect information on their ACEs and health risk behaviors. RESULTS: There were 58.3% (364) reporting some forms of ACEs, with 27.6% (172), 16.3% (102), and 14.4% (90) being exposed to 1, 2, and ≥ 3 ACEs, respectively. The prevalence of health risk behaviors ranged from 6.0 to 34.2%. Overall, ACEs were associated with increased risk of smoking, binge drinking, suicide attempt, risky sexual behaviors, and illicit drug use. Logistic regression suggested that participants with ≥ 3 ACEs (OR, 3.62; 95% CI, 2.14-6.13) were more likely to engage in the unhealthy cluster, characterized by the presence of any health risk behavior, than those without ACE. CONCLUSION: ACEs were associated with individual and clustering of health risk behaviors among Zambia college students. Our study suggests that early intervention is needed to prevent long-term adverse health consequences in this population.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA